As Covid-19 cases surge to their highest levels in dozens of states, the nation’s testing effort is on the brink of paralysis because of widespread delays in getting back results. And that is very bad news, because even if testing is robust, the pandemic cannot be controlled without rapid results.

This is the latest failure in our national response to the worst pandemic in a century. Since the Trump administration has abdicated responsibility, governors must join forces to meet this threat before the cataclysm that Florida is experiencing becomes the reality across the country.

Testing should be the governors’ first order of business.

Despite President Trump’s boast early this month that testing “is so massive and so good,” the United States’ two largest commercial testing companies, Quest Diagnostics and LabCorp, have found themselves overwhelmed and unable to return results promptly. Delays averaging a week or longer for all but top-priority hospital patients and symptomatic health care workers are disastrous for efforts to slow the spread of the virus.

Without rapid results, it is impossible to isolate new infections quickly enough to douse flare-ups before they grow. Slow diagnosis incapacitates contact tracing, which entails not only isolating those who test positive but also alerting the infected person’s contacts quickly so they can quarantine, too, and avoid exposing others to the virus unwittingly.

Among those who waited an absurdly long time for her results was the mayor of Atlanta, Keisha Lance Bottoms. “We FINALLY received our test results taken 8 days before,” she tweeted last week. “One person in my house was positive then. By the time we tested again, 1 week later, 3 of us had COVID. If we had known sooner, we would have immediately quarantined.”

Another complaint came this week from Mr. Trump’s former acting chief of staff, Mick Mulvaney, who wrote in an op-ed commentary for CNBC that “my son was tested recently; we had to wait 5 to 7 days for results.” Noting, too, that his daughter was told she didn’t qualify for a test, he added, “That is simply inexcusable at this point in the pandemic.”

As summer turns to fall, slow and fragmented testing will fatally undermine the reopening of schools and universities, whose plans are predicated on quickly identifying outbreaks and suppressing spread. Testing for millions of students will feed into an already failing national system.

Vice President Mike Pence’s casual invocation of an “extraordinary national success in testing” in a recent call with governors was flatly wrong, as is the president’s similar trumpeting of testing success. These claims contribute to a false sense among the public that testing may have had early stumbles but is ramping up slowly but surely.

The reality is that the spread of the virus has vastly outpaced the expansion of testing capacity. That spread in turn results in more illness and therefore more tests to process, which further slows down turnaround time in a vicious cycle. The dedication and patience of thousands of people waiting in serpentine lines of cars for hours to be tested are wasted when the results aren’t returned quickly enough.

We are at this point because of the absence of a coordinated federal plan, and, indeed, because of a White House that seems actively hostile to producing one. The nation’s governors and state legislators must fill the void.

Unity among the states is not just about neighborliness but also about self-interest. So long as interstate travel continues, inadequate testing anywhere threatens public health everywhere, including in places that have found or developed localized testing capacities and are less sensitive to the bottlenecks that Quest and LabCorp are experiencing.

The signal difference between federal and state leadership is that the former can print money and the latter cannot. If states are to step up, they will need resources: money from Congress without executive branch holdup, coordination and mutual aid from one another, and cooperation and expertise from the public itself.

Here’s what the governors need to do to bolster the overall testing capability before the end of the summer, best begun with a summit in the next two weeks.

Governors must work collectively to fill gaps in their own testing and contact-tracing programs. The National Governors Association helped in a similar effort to curb the spread of the Zika virus.

In March there was a mad scramble and competition for personal protective equipment. Now, the allocation of tests and test processing may end up in another free-for-all. A coordinated approach by all states would avoid that. Consistent metrics must be established for accountability and to identify trigger points that call for rapid policy responses. Acting in concert can make it easier to undertake tough or controversial decisions like ordering lockdowns when testing shows renewed spread.

Governors should also agree to assist in sharing local test processing capacity, including by university labs, so it is available wherever it is most needed. Relying largely on two large commercial testing companies, as we are now, has proved to be a major vulnerability.

For example, the Broad Institute of M.I.T. and Harvard has stepped up in Massachusetts with more testing capacity — so much so that it is not being fully used. But no process is in place for a doctor in, say, Arizona to prescribe a test that the Broad will process. That’s a problem that governors can help solve. They can also find ways to subsidize investments by labs to expand capacity, to help untangle medical insurance complications so tests are covered and to prompt innovations in testing.

In particular, they should encourage the academic and commercial sectors to develop, test and produce new, rapid, point-of-care testing. More broadly, they should recruit data scientists and experts in science communication ready to lend their skills to a unified effort.

We can’t allow the delays at Quest and LabCorp to mark the start of a downward spiral. Instead, we must marshal a nationwide strategy to place the United States in the ranks of other countries that are successfully beating back the pandemic.

Sorting out testing is foundational to slowing the spread of the virus. From there, governors can build a comprehensive national plan of attack. Doing so will require new forms of coordinated governance. In the absence of federal leadership, it’s up to governors to step to the fore.